In a typical multiple computer environment, a Local Area Network (LAN) or Wide Area Network (WAN) allows for each computer to be connected to several other computers such that the resources of each connected computer are available to each of the connected computers. In this networked environment, a dedicated keyboard, video monitor, mouse, audio output device, audio input device, and/or auxiliary peripheral devices may be employed for each computer.
Keyboard, video, and mouse (KVM) switches for allowing access and control of multiple remote computers have long been known in the art. Traditional KVM switches use direct point-to-point wiring among servers, switch hardware, and end-user consoles. Recently, KVM devices have begun utilizing Internet Protocol (IP) in order to allow users at a local computer to communicate with and control remote devices. Keyboard, Video, and Mouse over Internet Protocol (KVMoIP) technology utilizes conventional network infrastructures running Transmission Control Protocol/Internet Protocol (TCP/IP) to permit remote access and control of computers and other devices.
KVMoIP devices offer several advantages over traditional KVM switches. In traditional KVM switches, one generally has to run cables from each server to switch chassis, then run more dedicated cables from switch-to-switch, and run still more cables from switches to each end-user console. The cabling is not only costly, but laborious and requires both effort and knowledge in larger systems. Additionally, space becomes a consideration as these systems generally take up a large amount of room. KVMoIP systems offer a simplified solution to this cabling problem. The KVMoIP equipment can be anywhere the computers are, with short cables from the KVMoIP unit to the computers. Only one Category 5 (CAT 5) cable need be run from the KVMoIP unit to an Ethernet hub. This connection can also be done wirelessly, eliminating the need for the CAT 5 cable.
Additionally, KVMoIP systems make it easier to add more computers to the existing network. When computers need to be added, they do not have to be located in the same room or even same building as in analog based KVM equipment. All that is necessary is to plug in the KVMoIP unit into an accessible network. This design eliminates the need for more switch-to-switch wire runs, or other cable extenders.
KVMoIP devices generally connect directly to an IP network via a 10/100 Network Interface Card (NIC). Users accessing the KVMoIP device can select one or more of the switch inputs at any time and a number of independent user sessions are supported. Generally, in traditional KVM switches, only one switch computer can be displayed at any time.
KVMoIP software is also incorporated into the system. KVMoIP software features several methods of accessing a KVMoIP device. Local consoles, dial-up, and serial connections offer a backup. Often proprietary software is implemented within the KVMoIP device. Some other systems known in the art use web browsers, Virtual Network Computing (VNC) clients, etc. to access the KVMoIP devices.
VNC clients are remotely controlled software, which allow a user to view and interact with one computer (the “server”) using a simple program (the “viewer”) on another computer (the “client machine”) anywhere on the Internet. The two computers may use different operating systems. Special software is required on both the remote server and the client machine. Additionally, VNC clients operate on a peer-to-peer basis.
Intelligent Platform Management Interface (IPMI) has further advanced remote computer management over the few years. IPMI was developed as an industry standard allowing administrators or other users to proactively manage, diagnose, and reboot machines from a remote location. When used in conjunction with other management technologies, IPMI provides a valuable and useful addition. IPMI is implemented within a server and is independent of the server's central processing unit (CPU) and operating system (OS) allowing it to work on its own when the host processor is down. IPMI enables, inter alia, management of servers via the network, increased security (i.e., encryption and authentication requirements), serial over LAN (SOL) control, Remote Management Control Protocol Plus (RMCP+), and VLAN control.
The functions enabled through IPMI use can be performed via local management software or remotely from a management station via IPMI management protocol. However, IPMI does not solve every management need. Tasks such as re-directing Graphical User Interface (GUI) screens across a network or reading application data with Simple Network Management Protocol (SNMP) (i.e., a management service that provides information such as the number of requests a particular application has processed in a given time period) still require additional technology. Thus, IPMI should be considered complementary to other management technologies, rather than a replacement.
One KVM system known in the art discloses an extended range communications link for coupling a computer to a keyboard, video monitor, and/or mouse that is located remotely from the computer. The end of the link that is coupled to the computer has a first signal conditioning circuit that conditions the keyboard, video monitor and mouse signals. ‘Conditioning the video monitor signals includes reducing their amplitude in order to minimize the amount of “crosstalk” that is induced on the conductors adjacent to the video signal conductors during transmission of the video signals. This signal conditioning circuit is coupled to an extended range cable having a plurality of conductors that transmit the conditioned signals, power, and logic ground potentials to a second signal conditioning network. This second network restores the video signals to their original amplitude.
Another system discloses a communications link for use between a computer and a display unit, such as a video monitor, that allows these two components to be located up to three hundred (300) feet apart. An encoder located at the computer end of the communications link receives analog red, green and blue signals from the computer and inputs each signal to a discrete current amplifier that modulates the signal current. Impedance matching networks then match the impedance of the red, green and blue signals to the impedance of the cable and transmit the signals to discrete emitter-follower transistors located at the video monitor end of the cable. These transistors amplify the signal prior to inputting it to the video monitor. Concurrently, the horizontal synchronization signal is inputted to a cable conductor and its impedance is not matched to the impedance of the cable, thereby allowing the conductor to attenuate the horizontal synchronization signal and reduce noise radiation.
Yet another system discloses an extended range communications link for transmitting transistor-transistor logic video signals from a local computer to a video monitor located up to a thousand feet from the computer. The link includes a first signal conditioning circuit located at the computer end of the link for reducing the amplitude of the video signals received from the computer and biasing them to a selected potential, where after they are applied to discrete conductors of the link. A second signal conditioning circuit receives and reconstructs the transmitted video signals prior to inputting them to the video monitor. According to the system, performance of this process reduces the appearance of high frequency video noise on the keyboard clock conductor of the transmission cable, preventing keyboard errors.
A different system discloses a video signal multiplexing device for use with a single video monitor that is capable of selecting one video signal from a plurality of computers for display on the video monitor. The multiplexing device has three switch circuits, a control signal generating circuit, three voltage amplifying circuits, three current amplifying circuits, a synchronous signal selection circuit and an interface circuit.
Yet another system known in the art discloses a computerized switching system for coupling a user interface, including a keyboard, mouse, and/or video monitor to one of a plurality of remote computers. A first signal conditioning unit, located at the user interface, includes an on-screen programming circuit that comprises a switch, a processor, and memory and is used to overlay a menu of connected computers on the video monitor of the user interface. After a remote computer is chosen from the overlaid menu, the first signal conditioning unit receives keyboard and mouse signals from the local user interface and generates a data packet for transmission to a central cross point switch. This switch routes the data packet to a second signal conditioning unit located at the selected, remote computer. The second signal conditioning unit then inputs the keyboard and mouse commands into the keyboard and mouse connectors of the remote computer as if the local keyboard and mouse are directly coupled to the remote computer. Video signals produced by the remote computer are also transmitted through the cross point switch to the video monitor of the user interface. The horizontal and vertical synchronization video signals are encoded on one of the red, green, or blue video signals to reduce the quantity of cables required to transmit the video signal from the remote computer to the local interface's video monitor.
Still another system discloses a method for accessing, controlling and monitoring data located on a remote computer from a local host computer. The video raster signal at the remote computer is converted to digital form and compressed after it has undergone a cyclic redundancy check. Software located on the host computer is capable of decoding the compressed video information and displaying it to a user of the local host computer. The remote computer and the local host computer may be connected either via the Public Switched Telephone System (PSTN) using modems at either end or via standard cabling. The system is also capable of bi-directionally transmitting mouse and keyboard signals between the host computer and the remote computer.
Still yet another system discloses a video signal distributor that receives, processes, and distributes video signals received from one or more computers to a plurality of video monitors. The video signal distributor includes three transistor-based voltage amplifying circuits to individually amplify the red, green and blue video signals received from each computer prior to transmitting these signals to a video monitor. The video signal distributor also includes a synchronization signal buffering device that receives horizontal and vertical synchronization signals from each computer and generates new synchronization signals based upon the quantity of video signals that are output to the video monitors.
A final system known in the art discloses a system for network switching of computer peripheral data. The system claims essentially unlimited connection of servers to network workstations. It has one or more data converters that convert the keyboard, video and mouse signals into suitable format for transmission between a network of workstations and servers. A plurality of servers communicates over a corporate network (LAN, WAN, etc.). The KVM ports of the various servers are connected with a cable to converter boxes, which communicate with a maintenance network. The system also provides motherboard access to servers. When a user wishes to access a server, a user workstation communicates via the maintenance network with a corresponding converter for the desired server to gain motherboard access to the server. It requires two separate links: one for network access and one for motherboard access.
In view of the foregoing, a need clearly exists for a multi-channel, scalable KVMoIP system for remotely managing a plurality of remote devices from a plurality of user workstations. Further, the system should support IPMI, USB, video, keyboard, and mouse re-direction. Also, the system should include IPMI support for both IPMI over serial and IPMI over Ethernet. It should be able to combine various signals into a single communication path for remote device management. Finally, the system should provide power management of the remote devices.